On Thursday, London’s Mayor Boris Johnson announced the shortlist of bidders to supply up to ten further trams to Transport for London (TfL) for use on the city’s Tramlink network in Croydon. The trams will be used to supply additional capacity on the network between Elmers End, central Croydon and Therapia Lane — one of the most congested parts of the route.

TfL, who purchased the Tramlink network from Tramtrack Croydon Ltd. in 2008, announced the plans late January, after submitting the tender to the Official Journal of the European Union (OJEU) on January 29. According to the notice, the additional trams will operate approximately 75,000km per year, will be needed for “at least 10, but not more than 20 years” and can be either new build or existing vehicles that can be modified — at a reasonable cost — to run on the Tramlink infrastructure.

The tram fleet is currently made up of 24 Bombardier CR4000 trams, which were constructed for the opening of the 28km network between 1998 and 2000. 22 of these trams are currently needed to operate the three tram routes each day, and the new service is expected to require at least an additional five trams daily, bringing about the need for a boost to the fleet levels.

The shortlist to supply the trams consists of City of Edinburgh/CAF, Stadler (Stadler Pankow GmBH) and Pesa (Pojazdy Szynowe PESA Bydgoszcz S.A.Holding, and the the three consortia will now be invited to submit proposals to supply the additional trams. The Invitation to Tender will run for four weeks.

It is not currently known whether the bids made by Stadler and Pesa will be for new-build or second-hand vehicles, however the bid from Edinburgh/CAF is to use a number of the currently-dormant trams that were constructed for that city’s own tram network. The system has had several set backs since construction began, with the network now set to open in stages with a number of tram lines (but not the trams to operate them) being cancelled, leading to a large surplus of vehicles that could be hired out in the short term. The trams are amongst some of the longest and heaviest in Europe, though, and will require a large amount of modification to enable them to be able to operate on Croydon’s network if the bid is successful.

Shortly after the announcement, whilst inspecting one of the network’s current trams at East Croydon tram stop, Boris Johnson said: “I have no greater responsibility as Mayor than to ensure people can move around this city with ease, comfort and reliability.

“Trams in Croydon have proved a major success and this is reflected in journey numbers which have soared by 45 per cent since the network opened in 2000.

“I look forward to the extra vehicles developing this vital, much-appreciated, and indeed attractive, form of transport further.”

Funding for the new trams is expected to largely come from TfL, however the London Borough of Croydon has also confirmed a £3m contribution to the project. This will also include the refurbishment of tram stop surrounds.

Croydon Council Leader Mike Fisher said: “This is looking like a great deal for Croydon and shows the benefits of an ambitious local authority and committed Mayor working together, pooling resources and expertise.

“There is real support to get additional trams for Croydon to keep pace with growing demand for Tramlink services and also to secure major improvements for pedestrians and transport users around and between East and West Croydon stations.”

TfL anticipates that, providing a successful bid is made, the new trams would be delivered to the network’s depot at Therapia Lane in late 2011, with an entry into service from early 2012.